The Nova, on the first page.
I think the Nova edges it for me, it looks classic, well structured and without lots of branding. Has a short handle and a long (detachable) strap, has a good locking system but also a zip so people can't just ram their hands in your bag on the tube. Large enough to fit lots in but not absurdly big or floppy if not filled up enough. Seems to have a few internal compartments. Also doesn't have overt branding and I like the colour choice.
The Ramanga and the Kira are the only other two I'd consider.